Plastic compound of cellulose



' NrTnD STATES PATENT OFFICE.

CHARLES FREDERICK CROSS, EDl/NARD JOHN BEVAN, AND CLAYTON B'EADLE, OF LONDON, ENGLAND, ASSIGNORS TO HENRY G. NICHOLS, TRUSTEE, OF

BOSTON, MASSAOHUSET TS.

PLASTIC COMPOUND OF CELLULOSE.

SPECIFICATION forming part of Letters Patent No. 520,770, da J 11116 1894- Application filed October 15,1892. Serial No. 449.012. (No specimens-l Patented in France January 1o,1893.N -2 3 Belgium January 11, 1893, No. 103,093 in Ge anyJanuary 1 70,999; in England February 1893 8 and in Italy March 31, 1893,11'0. 33,347.

To aZZ whom it may concern.-

Be it known that we, CHARLES FREDERICK Onoss, EDWARD JOHN BEVAN, and CLAYTON BEADLF, subjects of the Queen of Great Britam, res1ding at No. t New Court, Lincolns Inn, 111 the city of London, England, have discovered a new and useful plastic compound of cellulose having peculiar properties which render it of great value in the industrial arts 10 and also a process of preparing the same, (for which we have procured Letters Patent of Great Britain, No. 8,700, dated February 6, 1.893; of Germany, No. 70,999, dated January 13, 1893; of France, No. 227,034, dated J anur5 ary 10,1893; of Belgium, No. 103,093, dated January 11, 1893, and of Italy, No. 33,347, dated March 31, 1893, and have also applied for Letters Patent of Austria-Hungary,) of which the following is a specification.

This new plastic compound may be rolled in sheets, or otherwise worked, onmOldgd, or,

it may be distended or dissolved in water. Upon decomposition it yields up cellulose in a new and useful form. It may be prepared 2 5 by a simple and comparatively inexpensive process hereinafter described.

As above stated this process also constitutes a part of our invention, as we believe 1t to be the simplest and best method of pre- 0 paring our new compound, but the compound ltself is our invention whether produced by this or some other process. lVe will now describe thisprocess which consists essentially, in first treating cellulose, oellulosic raw ma- 3 5 terlal or equivalent substances with a strong solution of an alkaline hydrate and then treatlng the mass with carbon iii-sulphide all as hereinafter more particularlysetforth, and as 1s pointed out in the claims which are ap- 0 pended hereto and made a part hereof.

In treating the cellulose according to our process, the material to be treated, for example, cotton in any of its forms, raw or manufactured, flax in the form of fiber or other- 4 5 wise, chemical wood-fiber, &c., is saturated in any convenient way with a strong solution of an alkaline hydrate, preferably caustic soda,

the strength of the solution being preferably from twelve to twenty per cent. of sodium oxide. When the mass has been uniformly 5o saturated, the excess of the alkaline solution may be removed in any well-known manner as by squeezing or pressing or by means of a centrifugal machine. The resulting mass, which then holds from twice to four times its 5 5 weight of the alkaline solution, preferably then is broken up, or loosened, and placed in a closed chamber. Into this chamber, carbondi-sulphide is introduced, the quantity employed being from ten to forty per cent. of the weight of the raw material that is of the cellulose originally employed. Owing to the volatility-0f the carbon di-sulphide, it rapidly diffuses itself in the form of vapor through out the chamber, and the mass of material6 contained therein. The uniform inter-action of the di-sulphide and fibrous material may be aided by employing a cylindrical or spherical chamber so mounted asto be capable of rotation throughout the period of action, or any means may be employed for agitating the contents of the chamber. The action of the di-sulphide may also be considerably accelerated by raising the temperature in the reac tion chamber, which, in this case, must be so constructed as to withstand the resulting increase of pressure. We prefer a temperature offrom 60 to Fahrenheit. It may be addedthat the penetration of the mass by the di-sulphide may also be promoted by exhaust- 8o ing the air from the reaction chamber and admitting the di-sulphide in the form of vapor. The action completes itself sufficiently for most purposes at the ordinary temperature in from three to five hours, but may be prolonged with advantage, when it is desired to produce a compound as free as possible from residual fiber. The product obtained from this treatment is a viscid mass, composed of a compound in which the essential 0 and characteristic component is cellulose, the same being combined with other constituents derived from the re-agents employed, and

.upon the addition of water the viscosity of the resulting aqueous solution is such that the mechanical aid of crutching or paddling is required in its production. By such aid, however, a homogeneous solution is rapidly produced. This aqueous solution is a solutlon 1n the ordinary and general sense of that word, and it may be regarded as a solution for all practical purposes; bntwe do not mean to imply that it is a true solution in the tech nical, chemical meaning of that word, as this 1s a point which we have not yet determined. It will be clear that the original viscid product may be employed for certain purposes without being distended or dissolved in water, or it may be so distended or dissolved, this subsequent treatment depending upon the uses for which the compound is to be employed. The viscid mass or the solution or mixture thereof may be treated for the removal of any undissolved portions or residual fiber by straining in any convenient manner. By the above described process a highly viscous bright solution or admixture is produced which may be employed for a large number of useful purposes.

If it be desired to remove from the compound the byproducts of the interaction of the reagents which are not essential to the compound, either in the plastic condition of the latter or after treatment of the same with water, such removal may be eltected by a suitable process of purification, as by precipitation by alcohol, or by a saturated solution of sodium chloride, and decantation, but the methods of purification need not here be descrlbed as they form no part of our present invention. It will alsobe clear that our pro cess is equally available for bringing about the partial conversion of fibrous materials; thus, it cotton or linen fiber be employed, the action may be arrested at any period short of that required for the complete conversion and the product is available for use without treatinent with water, or if treatment with water 1s employed a mixture of the compound above described with residual fiber in any desired proportions is obtained and such a mixture would be preferred for many purposes. There are also certain raw fibrous materials which yield incompletely to the action of the re-agents above described. If these be employed a mixture is obtained of the viscid product above described with a'certain proportion of fibers and cells which resist the action and such mixtures are available for many special purposes. Our compound is directly applicable to many valuable uses, such as sizing and filling paper and cloth. For sizing paper, our compound preferably after treatment with water may be added directly to the stock in the beating engine, after which alum is added as with ordinary rosin size. For sizing cloth either the threads or the fabric may be passed through the solution and then dried and washed. The solution may be used as an adhesive vehicle for carrying clay or other fillers, in case of either cloth or paper.

Many of the various valuable materials which may be prepared through the decomposition of this plastic and soluble compound are fully described together with the method of their manufacture and the method of effecting the said decomposition in our application for Letters Patent filed the 16th day of August, 1893, Serial No. 483,279, to which reference may be had.

In practicing our process, we do not desire to limit ourselves to the successive treatment of the raw material by a caustic alkali and the di-sulphidc of carbon as the raw material may be treated with alkaline solution and the di-sulphide simultaneously if preferred.

What we claim is- 1. The plastic compound of cellulose herein described which is soluble in water.

2. The process herein described ot producing a plastic compound from cellulose .or equivalent substances which consists in subjecting such substances to caustic alkali and carbon di-sulphide, substantially as set forth.

3. A soluble compound derived from cellulose, caustic alkali and carbon di-sulphide, substantially as set forth.

In testimony whereof We afiixoursignatures in presence of two witnesses.

CHARLES FREDERICK CROSS. EDWARD JOHN BEVAN. CLAYTON BEADLE. Witnesses:

WILMER M. HARRIS, THOMAS LAKE, Btgth 07f l7 Gracechm'ch Street, London, Eng- 

